08.21.2019

How to add swap on Centos

To make your server can handles big processes or do memory cache. You should add swap on server if you not have to much ram

Make Swap file

$dd if=/dev/zero of=/swap bs=1M count=1024
$chmod 0600 /swap

then begin to mount your swap file
$mkswap /swap
$swapon /swap


To check your swap
$ free -m

Te make swap enable automatically each time reboot

vim /etc/fstab

paste below line into the end of file

/swap swap swap defaults 0 0
 

Recommended swap size

RAM Size Swap Size (Without Hibernation) Swap Size (With Hibernation)
256MB 256MB 512MB
512MB 512MB 1GB
1GB 1GB 2GB
2GB 2GB 3GB
3GB 2GB 5GB
4GB 2GB 6GB
6GB 2GB 8GB
8GB 3GB 11GB
12GB 3GB 15GB
16GB 4GB 20GB
24GB 5GB 29GB
32GB 6GB 38GB
64GB 8GB 72GB
128GB 11GB 139GB

Hope this help

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